European Journal of Biomedical and Pharmaceutical Sciences

HISTOMORPHOLOGICAL EFFECT OF RAUWOLFIA VOMITORIA AFZEL ON THE PONS OF SLEEP-DEPRIVED WISTAR RATS

*Yorkum Leyira K., David Lekpa K., Hart Josiah S. and Okenwa Chinemerem A.

ABSTRACT

Insomnia is a condition where sleep latency is greater than thirty minutes, sleep efficiency (time asleep/time in bed) is less than 85% or sleep disturbance more than three (3) times a week. The aim of this study was to ascertain the histomorphological effect of Rauwolfia vomitoria Afzel on the pons of sleep-deprived wistar rats. The aqueous leaf extract was obtained by the rotary extraction method. Thirty (30) animals were used in the experimental protocol; they were acclimatized and randomly distributed into six groups of five animals each. Group 1 served as the control, group 2 (non-insomnia induced treated with 20mg/kg of the extract), group 3 (insomnia-induced only), group 4 (insomnia-induced that was treated with 1 ml Diazepam), group5 (insomnia-induced that was treated with 10mg/kg of R.vomitoria) and group 6 (insomnia-induced that was treated with 40mg/kg of R.vomitoria). Sleep disturbance was established using a sleep tracker. Drug administration was for seven days. Anxiogenic behavioral pattern was observed using the elevated plus maze. The animals were anaesthetized, the pons extracted and processed histologically for paraffin wax embedding, sectioned, stained with Hematoxylin and Eosin (H and E) and viewed with a light microscope after which photomicrographs were obtained. Photomicrographs served as results and provided the basis for comparative studies. Histological sections of the insomnia-induced group revealed highly degenerating pontine cell bodies and in some cases disappearance of nucleus and degenerating pontine neurons. Sections of the insomnia-induced animals that were treated with a low dose (10mg/kg) of R.vomitoria extract revealed scattered reappearing nucleus with more vacuolations as compared to the insomnia-induced animals treated with Diazepam and insomnia induced animals treated with a high (40mg/kg) dose of R.vomitoria extract. The study indicates that the aqueous leaf extract of Rauwolfia vomitoria in high doses are of more therapeutic effect in ameliorating insomnia.

Keywords: Rauwolfia vomitoria Afzel, histomorphological, insomnia-induced, pons, wistar rats.